CVE-2026-34926
Published 2026-05-21 · Updated 2026-07-23 · Source security@trendmicro.com
Summary
CVE-2026-34926 is a medium-severity (CVSS 6.7) vulnerability in Trend Micro Apex One. CISA added it to the Known Exploited Vulnerabilities catalog on May 21, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by June 4, 2026. CISA does not currently list it as used in ransomware campaigns. Trend Micro has 12 vulnerabilities in the KEV catalog, 0 of them linked to ransomware.
All 12 known-exploited Trend Micro vulnerabilities →Description
A directory traversal vulnerability in the Apex One (on-premise) server could allow a pre-authenticated local attacker to modify a key table on the server to inject malicious code to deploy to agents on affected installations. This vulnerability is only exploitable on the on-premise version of Apex One and a potential attacker must have access to the Apex One Server and already obtained administrative credentials to the server via some other method to exploit this vulnerability.
CVSS vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
CISA Known-Exploited Vulnerability
Product: Trend Micro — Apex One
Name: Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability
Date added: 2026-05-21 · Due: 2026-06-04
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.